1996 OHV 4.0 Explorer Head/Head Gasket Replacement Question(s)

[Foxhound_22]

im doing the same on mine i am new to this 4.0 ohv im use to a 5.4, so i got lucky with the passenger side header bolts came out fine fingers crossed that the driver will come out, i have a newb question? do i have to remove the lower intake manifold off to remove the heads?!

 

[Dono]

Yup
Lower intake, valve covers, rockers, push rods.

 

[Foxhound_22]

Yup
Lower intake, valve covers, rockers, push rods.

okay thanks for the info!!

 

[Foxhound_22]

is the lower intake suppose to be hard to get out?

 

[Dono]

no, its easy.
once you have the upper plenum off, your away to the races.
Upper plenum comes off, and then leave the injectors mounted.
You will then see the bolts holding down the lower intake. remove those.

Sometimes the rtv makes it a but of a tug to pull the lower intake off. I have used a well placed prybar to break the seal if it is being stubborn.

There is a pdf around on lower intake gasket replacement. google 40LIntakeGasketReplacement.pdf that will clear up your questios.

 

[Foxhound_22]

no, its easy.
once you have the upper plenum off, your away to the races.
Upper plenum comes off, and then leave the injectors mounted.
You will then see the bolts holding down the lower intake. remove those.

Sometimes the rtv makes it a but of a tug to pull the lower intake off. I have used a well placed prybar to break the seal if it is being stubborn.

There is a pdf around on lower intake gasket replacement. google 40LIntakeGasketReplacement.pdf that will clear up your questios.

thanks a bunchs i just got it off had to pry it, working with a new motor an all i was just worried about breaking some thing, all i have left is the drive side header then the heads!
Thanks again an sorry for the newb questions!

 

[Dono]

No worries on the questions.
The first time is the hardest. If you do it again, it will take no time at all.

 

[keleko17]

I am not a mechanic, but decent at removing and replacing parts. The heads sound like it might be a little above my pay grade, but if I decide to get into it, how do I know if I need to replace lifters, valves, etc?

I don't want to do the work, only to find out that I should have gone just a little deeper.

 

[Dono]

best thing on the heads would be to take them to a reputable machine shop.

Then you need to look at lifters. With them out of the block, you can set them on a table and see if any are quite a bit lower than the others. If some are, they are collapsed. Ive read about quite a few guys that replaced theirs and are having issues.

Are you hearing ticking from the motor at idle? It would be fairly loud.
Why Im asking is rocker arms and push rods might be worn and clearances are sloppy.

 

[travsbengals]

I'd recommend taking the heads to a machine shop to have them resurfaced anyhow

I'm a shade tree mechanic and although it took awhile, this job wasn't terribly difficult thanks to this website. I have a small oil leak I need to fix but no anti-freeze leaks. Truck runs good

I get the ticking now, should have replaced the pushrods.........

Label everything and take notes

 

[travsbengals]

PS Don't use cork valve cover gaskets

 

[Dono]

PS Don't use cork valve cover gaskets

If you really want the cork ones, I have a new pair I can send you. Use at your own risk.

 

[keleko17]

I think I have decided that this is likely the first of many more mechanical issues on the horizon for this vehicle. I can't justify putting the time / money into it.

Which means it is now going to be parted out to the highest bidder, then I will use it for auto extrication classes as a volunteer firefighter.

 

[Runnin'OnEmpty]

I say buy the heads, do. A mild port and polish yourself, and pull the front of the motor apart while your at it and replace the cam with something that breathes better.

Where do you stop once you start? That's the million dollar question.

Where do you stop indeed....I've been keeping up with
your postings in the "Need for Speed" section. Good
looking engine!

I lifted off the passenger side head tonight. At first I
found nothing.....was sure the #1 cylinder would have
a crack. Then I pulled the headgasket off and found a
very small defect/gasket tear where the water jacket
'dead-ended' into the gasket. It was apparent this
was where coolant was entering #1.

FelPro sells a gasket set that's for severe duty and
commercial vehicles; that's what I'm re-installing.
They seem to be slightly stiffer and more robust
than the stock ones. I'll post back if and when the
pile of parts gets together again....

 

[Dono]

Got to love finding the issue. You taking the heads in to have them checked over? I'm sure you will get it back together easily. There is always that little lingering doubt in the back of your mind...'what if things go horribly wrong'.

You will be fine.
I like the HD Head gasket thing.

 

[Runnin'OnEmpty]

.......You taking the heads in to have them checked over? I'm sure you will get it back together easily. There is always that little lingering doubt in the back of your mind...'what if things go horribly wrong'.
........

I have one new cylinder head that I'm installing on
the passenger side, even though the existing head
looks good. There's a nagging doubt in the back of
my mind that says it might be warped. Haven't
checked it yet.

What's worrisome is that this head has been pulled
before. Everything looks good inside, with virtually
no wear and little carbon, so I'm confident it truly
has only 60K miles on it. But it had a FelPro head-
gasket installed.

Any potential problems with running just one new
head...?

 

[Dono]

I bought new heads complete, and just slapped them on.

Then a very bad thing happened....
Low compression in a cyl (Cant remember which one). It would cause a violent motor shake.

I pulled the head off and found a piece of brown packing stuff that the heads were shipped in stuck inbetween the valve and its seat to the head.
After that experience, Id take even a new head in to have it vacuum tested to make sure the valves are seating properly.

There's just so many little things that can go wrong. I'd have never imagined that something silly like a bit of pavking material could get stuck in such an odd spot and hold a valve open slightly.

 

[Runnin'OnEmpty]

......I pulled the head off and found a piece of brown packing stuff that the heads were shipped in stuck inbetween the valve and its seat to the head........

Wow, what a horror story on Halloween. That must
have been very frustrating. After your warning, I checked
mine over very carefully. It's an Alabama cylinder head
and the casting looks very good, much better than the
original Ford head. Smoother and more 'precise' looking.

This is a crude test I know, but I checked the old head
with a carpenter's level and it looks to be warped, when
compared to the new head. This would explain a lot;
the failed headgasket at #1, and the fact the head has
been off before (put back with FelPro instead of Ford
headgasket). Whoever worked on it obviously didn't
check the head, and the headgasket probably failed
again soon afterward...

 

[Dono]

Im sure you will be fine. What happened to me was very unusual.
Just take your time and look closely at everything, like your already doing.

Excellent that you can see the issue with the head that was installed previously. That makes a guy way more comfortable as the repair progresses. Nothing worse than pulling everything apart, and not finding an issue anywhere.

 

[Runnin'OnEmpty]

I just got this puppy back together last week, and
have only put a few miles on it, but it now runs great!
No tailpipe vapor, no coolant bubbles, no shaky cold
start-up, no misfire, nothing. I think it's fixed.

Here's a pic of the failed headgasket. It has a tear
at the 1 o'clock position looking from the sparkplug.
Notice the discolored number 1 plug. That was my
first clue and narrowed the problem down to
the number 1 cylinder.